Improvement in latches



O. H. .ISMITH. Latch.

m. 216,904. Patentedlun 24, 1879 B FIG-I.

FMS/2.

INVENTOR NFETEHS. PHOTD-LITMOGRAPHgH. WASHINGTON, D c.

TINI'TED' STATES PATENT QnnmE;

CHARLES H. SMITH, OF NEW HAVEN, ASSIGNOR TO THE RUSSELL & ERWINMANUFACTURING COMPANY, 'OF NEW BRITAIN, CONNECTICUT.

IMPROVEMENT IN LA TCHE'S.

Specification forming part of Letters Patent No. 216,904., dated June24, 1879; application filed April '28, 1879.

To all whom it may concern:

Be it known that I, CHARLES H. SMIrmof the city and county of New Havenand State of Connecticut, have invented a certain new and usefulImprovement in Door-Latches; and I do hereby declare that the followingspecification, taken in connection with the accompanying drawings,forming a part of the same, is a full, clear, and exact descriptionthereof. V

The improved latch hereinafter described belongs to that class in which,upon the complete closing of the door, the latch-bolt previously heldback within the case is permitted to be projected into the mortise inthe doorjamb for the purpose of securely holding the door.

In my invention a square insteadof a bev el-faced IEI-tCll bOIh isemployed, and which is at all times housed within the latch-case unlessacam-faced lever, which projects beyond bined with the latch-bolt, ashereinafter eX-' pla'ined, is pressed inward, in which case, if the doorbe open, the bolt will be moved outward as the lever is moved inward,but if the door be closing and the face of the latch be.

abutting against any part of the door-jamb or usual striker-plate, thelatch will beheld within the case until the door isfully closed,notwithstanding that the operativecam-faced lever is moving inward. Themovement of the said lever, however, inward winds up a spring, whichreacts when the bolt is in line with the mortise in the jainb, andprojects the bolt forward to hold the door fast.

The construction shown in the drawings exhibits several advantages. Inthe first place, the cam-faced lever projecting beyond the faceplatepresents a slight frictional resistance to the door in closing. Again,inasmuch as this lever operates to cause the bolt to be projected.forward instead of operating to force a latch inward, as in the case ofordinary lever-latches, a square-headed latch-bolt can be employed,which has the advantage of great strength; but especially is thisarrangement important, for the reason that when the bolt is shot forwardafterthe door is closed it is impossible.

to insert a knife blade between the striker plate and the edge of thedoor and push back the bolt, whereas in all leverlatches operat' ing topush the latch inward a bevel-faced" r In my improved latch thecam-leveris held inward by contact with the striker at all times when the door isclosed, and pressure against it has no tendency to move the latch-boltbackward.

Referring to the drawings, Figure 1 represents a view of the latch withthe bolt in its rearward position, thecap-plate beingremoved. Fig. 2shows the same with the bolt projected.

Fig. 3 represents a'seetion of the faceplate-on line as .40, showing theprojecting operating-lever hinged thereto, and Fig. at represents amodification of certain parts of the latch. the plane of the face-plate,and whichis co1n-- As shown in each of the figures, A represents thecase of the latch; B, the face-plate of the same; 0, the hub, and D thelever worked by the knob-spindle towithdraw the squarefaced bolt E whenthe door is closed. Hinged to the face-plate B is a vibrating cam-facedlever, F, which has a salient face projecting beyond the face-plate for.the purpose of im pinging against the striker-plate when the door isclosing. Engaging the rear face of this lever, as shown in Figs. 1, 2,and 3,1s the long arm of a bell-crank lever, Gr,p1voted to the case, andprovided with a flat spring, H, which keeps the levers G and F incontact.

The short arm of this lever G is furnished with one or more teeth, whichmesh with the teeth of anotherbell-crank lever, K, also pivoted to thecase A. Upon the pivot K of the lever K is arranged a coil-spring, L,the short arm, 1, of which engages a pin, k, on the short arm of thelever K, the long arm, Z, of said spring engaging a lug, c, on thelatch-bolt. The long arm of the lever K engages a lug, e, on the bolt E,and by the force of the springs H and L tends to keep the said bolt inits rearward position.

As shown in Fig. 1,. when the bolt E is housed in the latch,:which isalways thecase whenthe door is open, the lever D is not in contact withit, and can in no way exert an operating force upon it. Under theseconditions, if the cam-faced vibrating lever F should be worked, thespring L would act only as a lever, and move the bolt E outward andinward simultaneously with but in a direction opposite to that of themovement of the vibrating lever F, the spring H returning the parts totheir respective positions shown in said figure. When the door closes,however, the spring L takes on its proper function, and no longer actsas a lever, but as a spring, as will now appear.

During the movement of the door to a closed position the projectingvibrating lever F comes in contact with the striker-plate, and is turnedbackward upon its pivot. This movement operates the'levers G and K, andtends to advance the bolt by the lever action of L. The outward movementof the bolt, however, is prevented until the mortise in the strikerplateis in line with the head of the bolt, which does not occur until thedoor is fully closed and the lever F moved to its farthest rearwardposition. The bolt, therefore, being thus pre vented from advancing bythe striker-plate during the backward movement of the lever F, the longarm of L remains in position, while its short arm, Z, moves with thelever K, as

shown by broken lines at Fig. 1. This winds up and increases the forceof the spring L, so that when the mortise and bolt-head become alignedit discharges its spring function, and projects the bolt into themortise by a movement of its arm Z, the parts assuming the positionshown by full lines at Fig. 2.

The forward movement of the bolt brings its tail into contact with thelever D, in which position the bolt is retained by the spring L, readyto be withdrawn by the lever D when operated by the knob-spindle for thepurpose ofopening the door. When this lever is moved and the boltretracted the spring L would resume its lever function were it not thatthe vibrating lever F is prevented from advancing, because of itscontact with the strikerplate. The levers G and K, therefore, remainstationary, and only the long arm, 7/, of the spring L is moved by thebolt. This increases .the force of the spring by winding it up, as

shown by broken lines in Fig. 2, so that when the bolt'has beenretreated into its case, and the lever Fis allowed to advance by theopening of the door, the lever will be projected into its originalposition beyond the latch-face by the joint action of the springs L andH.

Although, as hereinbefore described, a bellcrank lever, D, is used toretract the bolt for the purpose of opening the door, and levers G K areemployed to increase the tension of the spring L, yet a common yoke maybe substituted for the lever D, and a single lever for the levers G K.Such a modification is shown at Fig. 4, where D represents the yoke inengagement with its hub and overlying the tail of the bolt, a spring,cl, operating to keep the parts in the position shown. vibrating lever Fis engaged by an arm, 9, which is pivoted to a lever, G, and controlledby the spring H. The lever G is pivoted to the latch-case, and its end 9is in contact with the bolt. The spring L is placed upon the pivot ofthe lever G, and its ends respectively engage the end g of the lever Gand the head of the bolt E. Under this arrangement the spring L performsthe same functions as the spring L, the lever G the same as the levers Gand K, the spring H the same as the spring H, and the yoke D the same asthe lever D. The movements of the bolt E and vibrating lever F,therefore, are the same as before specified.

From the foregoing description it will be seen that when the door isopen the latch-bolt will be housed in its case so long as the lever Fprojects to its full extent beyond the faceplate B 5 that should theleverF be moved when the door is in this position, the bolt will beoperated simultaneously with but opposite in direction to the lever bythe lever function of the spring L or L, and that when the lever Fceases to be manipulated the spring H or H will house the bolt andproject the lever into the proper position for the closing of the door.It will also be seen that when the door is closing or opening themovements of the lever F and bolt E are not simultaneous, but that thecomplete movement of one is followed by the complete movement of theother, the spring L or L performing its true spring function to advancethe bolt or project the lever F, as the case may be.

Having described my invention, what I claim, and desire to secure byLetters Patent, 1s-- 1. The combination of a vibrating lever piv oted tothe latch-case and projecting beyond the face-plate, a sliding bolt heldback by spring-pressure within the latch-case, and intermediateoperative mechanism, substantially as described, whereby the bolt will,by leverconnections, be moved outward as the vibrat ing pivoted lever ismoved inward unless the bolt is forcibly held back, but if so held themovement inward of the said lever will wiim up a spring in readiness toproject the bolt so soon as the obstacle is removed, as set forth.

2. The combination of a vibrating cam-lever pivoted to the latch-caseand projecting beyond the face-plate, a lever or a connected train oflevers within the latch case and oper ated by the cam-lever, a slidingbolt held back within the latch-case, and a spring which is wound up bythe movement of the cam-lever inward, substantially as and for thepurpose specified.

3. The combination ofa sliding latch-bolt, a lever or a connected trainof levers operat ing under spring-pressure to slide the bolt into andretain it within the latch-case, and a flexible spring-lever, L,arranged to throw the The projecting bolt forward when the bolt isrelieved of the pressure which tends to hold it back, substantially asdescribed.

4. The combination, as substantially before set forth, of i the slidingbolt, the hub and its arms worked by the knob-spindle, suitablemechanism connecting the bolt with the hub, mechanism, substantially asdescribed, for retracting the bolt independently of the knob spindle andits connections when the vibrating cam-lever is not pressed inward, andmechanism, substantially as described, for projecting the bolt when thedoor is fully closed.

"lever and its connections for working the vi.-

brating lever, substantially as described.

' CHARLES H. SMITH.

' Witnesses:

THEo. E. SMITH, H. E. RUssELL, Jr.

